Non-fluorinated adamantane derivatives are useful as compounds to constitute etching resistant thin film materials for protecting substrate layers in an etching process employing photolithography (JP-A-2001-60583).
For high densification in order to meet an increase in the amount of information, photolithography employing a laser beam with a shorter wavelength is adopted. However, with conventional adamantane derivatives, the transmittance to such a laser beam has been inadequate.